1. Field of the Invention
The subject invention generally pertains to playground equipment and more specifically to a seesaw.
2. Description of Related Art
A seesaw is a well-known piece of playground equipment that comprises a pivotal beam balanced on a fulcrum. Two children typically sit at opposite ends of the beam to teeter up and down.
When the two children are of equal weight, they can sit the same distance away from the fulcrum, and the seesaw will be balanced. If there is a weight difference between the children, the seesaw may be imbalanced.
To compensate for such an imbalance, some seesaws include a feature for adjusting the location of the fulcrum relative to the beam, thereby adjusting the relative distance that each child sits away from the fulcrum. U.S. Pat. No. 2,431,138, for example, discloses a seesaw whose balance can be adjusted by selectively setting the beam upon a fulcrum at different points along the beam. Another seesaw, disclosed in U.S. Pat. No. 5,951,406, is balanced by way of an adjustable telescopic beam. Although such adjustable seesaws are effective, they do have their drawbacks.
For the seesaw of the '138 patent, the adjustment mechanism appears to pose a finger pinching hazard as the plank needs to be lifted and set back down in order to adjust its balance. Moreover, two people may be needed at opposite ends of the plank to lift and reposition it. If just one person adjusts the plank, that person would likely lift the plank near its center of gravity, but that is where the potential pinching hazard exists. In operation, if a child “pushes off” especially hard, the child might dislodge the plank from its adjusted position.
For the seesaw of the '406 patent, shot pins help hold the telescopic beam at its adjusted position. If someone fails to install those pins, the seats could unexpectedly slide all the way in or fall out entirely. This could suddenly create a drastic and dangerous imbalance.
Consequently, a need exists for a seesaw that is easier and safer to adjust.